This invention relates to tape guides for use in magnetic tape cassettes, and more particularly to high-precision magnetic tape guides of a material-saving type and also to a method of manufacturing the same.
Magnetic tape cassettes commonly use tape guides for guiding a magnetic tape within the cassette housing. FIG. 1 illustrates typical tape guides used in a magnetic tape cassette of the VHS system. As shown, the magnetic tape cassette comprises an upper housing section 1 and a lower housing section 2 which are mated together, with a front lid 3 pivotally connected to the front part of the upper housing section to form a closed cassette housing, a pair of reels held within the housing, each reel having a set of lower and upper flanges 4, 6 or 5, 7, a presser plate spring secured to the inner surface of the upper housing section 2 to exert a pressure against the reels in position, and a length of magnetic tape 9 affixed to and wound on the reels so as to be drawn out to pass an open front region of the housing. Numeral 10 designates a window panel adapted to fit in a seethrough window of the upper housing section 10.
Along the path of the magnetic tape are located various guide members. In the front part of the lower housing section 1, there is set upright a pin 11 of plastics or metal, over which is fitted a plastic guide roller 12. Another plastic pin 13 is fitted with a tubular guide 14 of stainless steel. Similarly, a plastic pin 15 is encased in a stainless steel tubular guide 16. A metal pin 17 also is provided.
Thus at least one of the magnetic tape guides consists of a metal tube. Such a guide has the disadvantage of increasing the material cost accordingly.
As an attempt to overcome the problem it has been proposed, for example, by Japanese Utility Model Application Publication NO. 5660/1986, fix an arcuate metal leaf on a support post of plastics or the like. The method reduces the material cost but is unable to secure adequate dimensional accuracy required of the guide. This is because polishing the arcuate metal leaf with high precision involves difficulties, and if the end is to be attained anyhow, additional expenditure will be necessary for the polishing process.